Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;
import java.*;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Random;
import java.lang.*;
 



 
 
public class zad {
private static BufferedReader in;
private static StringTokenizer tok;
private static PrintWriter out;
final static boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") !=null;
 
public static void init() throws FileNotFoundException{
if(ONLINE_JUDGE){
in = new BufferedReader(new InputStreamReader(System.in));
out = new PrintWriter(System.out);
}
else{
in = new BufferedReader(new FileReader("input.txt"));
out = new PrintWriter("out.txt");
}
}
 
private static String readString() throws IOException {
while (tok == null || !tok.hasMoreTokens()) {
tok = new StringTokenizer(in.readLine());
}
return tok.nextToken();
}
 
private static int readInt() throws IOException {
return Integer.parseInt(readString());
}
private static double readDouble() throws IOException {
return Double.parseDouble(readString());
}
private static long readLong() throws IOException {
return Long.parseLong(readString());
}
private static float readFloat() throws IOException{
    return Float.parseFloat(readString());
}
 
 
 



public static void Solve() throws IOException{

    String st = in.readLine();
    ArrayList<String> mas = new ArrayList<String>();
    
    int ans=0;
    for(int i=0;i<st.length();i++){
        if(Character.isLetter(st.charAt(i))){
            String f = ""+st.charAt(i);
            boolean b=true;
            for(int j=0;j<mas.size();j++){
                if(f.equals(mas.get(j))){
                    b=false;
                    break;
                }
            }
            if(b){
                mas.add(f);
                ans++;
            }
        }
    }
    out.print(ans);
    
        
}
    
    




public static void main(String[] args) throws IOException {
init();
Solve();
 
 
in.close();
out.close();
}
}